While various types of aircraft have been designed in the past specifically to accommodate cargo loads as opposed to passengers, it is relatively commonplace for cargo haulers to utilize modififed passenger craft for these purposes. Many passenger craft designs include a forwardly disposed wheelbase configuration vis-a-vis the fuselage of the craft, an efficient and highly preferred design whether the aircraft be used for transporting passengers or cargo. However, one pronounced drawback in the context of cargo loading and unloading is a tendency for tail rocking about the main gear at times when the principal load is confined to the tail region of the craft and the center of gravity shifts in that direction; as occurs typically upon initial loading or near the end of unloading procedures. As can readily be imagined, where the load is housed only or principally within that tail region at such times, this type of destabilization or rocking is at the least troublesome and indeed can be damaging to both craft and cargo let alone pose emergency risk to the flight and/or ground crews.
A common expedient to overcome tail rocking during these times of cargo loading and unloading is simply to employ an aircraft jack to stabilize the tail of the craft. While that straightforward technique is a simple solution to the problem, maintaining the craft in its proper orientation while there is no forwardly disposed load countering that in the tail, it is not altogether satisfactory. Ground equipment of this sort has a surprising tendency to become lost or misplaced during normal airport operation. The equipment is oftentimes relatively complicated due to the requirement that it provide a constant load in spite of the changes in jack height as the airplane is loaded and/or unloaded, and that has rendered the same very susceptible to handling and use damage. Such damage interferes with the availability of the equipment which is problematic at best because there is no certain way to predict how many jacks will be needed at an airport at any one time or indeed where within the facility they may be needed. Availability or lack of it becomes increasingly serious with increases in the amount and diversity of air cargo services; a factor exacerbated when one considers the paramount importance of speedy loading/unloading for those cargo haulers devoted to handling letters and small packages, demanding frequent stops at many airport locations. Furthermore, considerable care must be exercised in order to avoid damaging the aircraft by improper use of the jack and, with more frequent and diverse usage, the damage hazard is likely to increase.
The prior art, of course, recognizes all manner and variety of jacking devices for lifting and/or stabilizing various types of vehicles including motor vehicles and aircraft. Exemplary of various aircraft jacks as components of ground equipment are those disclosed in U.S. Pat. Nos. 2,314,589, 2,369,545, and 2,392,786. In some instances, stabilizing structures are incorporated directly within a motor vehicle or aircraft. In the context of aircraft, U.S. Pat. Nos. 2,497,489 and 2,533,925 are representative. U.S. Pat. No. 1,957,151 is noteworthy for a disclosure of an airjack system disposed within a motor vehicle; comprising a central air reservoir in selective communcation with jack units associated with each wheel, whereby a preselected one of the jacks may be actuated to raise the vehicle at that location. Somewhat similar is the hydraulic jack unit of U.S. Pat. No. 2,194,594. Of general background interest are U.S. Pat. Nos. 2,391,384, 2,572,409 and 3,315,942; all of which deal with jack or stabilizing devices associated with a motor vehicle but none of which adds to the general scope of the references cited above.
As is now plainly evident from the foregoing background description, it would be desirable to provide a tail stabilization member specifically adapted for use in conjunction with a cargo aircraft in order to guard against tail rocking or like destabilization during loading and/or unloading procedures; one which eliminates the disadvantages of using conventional ground equipment for that purpose; and one which takes into account the most efficient and proper placement of the device vis-a-vis the craft to minimize the potential for damage to the latter while maximizing the simplicity and operational efficiencies of same in use.